Triethylenglycol as Novel Heat Transfer Fluid for CPVT Collectors with Spectral Splitting

State-of-the-Art of Concentrating Photovoltaic Thermal Technology

“…These investigations were performed under the assumption that an optical filter fluid is available with ideal optical, hydraulic and thermal properties. This premise could be appraised as quite optimistic for the perspective of real feasibility, as experimental research has already shown [21,23]. Furthermore, the implementation of vacuum gaps Huang et al [22] performed comprehensive optical, electrical and thermal modelling of their receiver design, investigated different upper and lower thresholds for the optical filter fluid, and considered two different kinds of PV technologies (Si and CdTe).…”

“…The temperature of the PV module remained below 100 • C. These investigations were performed under the assumption that an optical filter fluid is available with ideal optical, hydraulic and thermal properties. This premise could be appraised as quite optimistic for the perspective of real feasibility, as experimental research has already shown [21,23]. Furthermore, the implementation of vacuum gaps formed by glass channels with rectangular cross-section could be challenging in terms of mechanical stability.…”

“…However, the simplification of the spectral splitting mechanism to only one filter element is linked with a reduced degree of freedom in terms of wavelength selection. Applicable fluids usually have a characteristic decrease of transmittance for long wavelengths, which meets the exact requirements for the spectral splitting approach (see Figure 1), but the desired absorption of short wavelengths by the fluid is mostly not provided, as experimental transmissivity investigations have shown [16,17,21,23].…”

“…According to the opinion of the authors, the constructive design of a spectral splitting CPVT receiver should not be too complex, because if this technology shall overcome its niche status on the long-term perspective, it must also be economically viable in the future. Therefore, the research work of the authors focusses on spectral splitting by selective absorption, because this approach appears to be promising for developing compact CPVT receivers with a high probability of being experimentally feasible [12,[16][17][18][19][20][21].…”

Optical Modelling of a Linear Fresnel Concentrator for the Development of a Spectral Splitting Concentrating Photovoltaic Thermal Receiver

“…One of the novelties of their construction is the utilisation of bendable CIGS PV modules representing the electrical receiver part [16]. Secondly, triethylene glycol was successfully tested for its implementation in the CPVT receiver, both as a heat transfer fluid and as the liquid part of the required optical filter [17]. During the receiver design process and for the subsequent stage of experimental realisation, detailed knowledge about the optical performance of the considered Fresnel mirror field was required.…”